Fennel affects ovarian cell proliferation, apoptosis, and response to ghrelin

The objective of this study was to examine the direct effects of the medicinal plant fennel (Foeniculumvulgare Mill.) on basic functions of ovarian cells, including proliferation, apoptosis, and response to the physiological hormonal stimulator, ghrelin. In the first series of experiments, porcine ovarian granulosa cells were cultured with (1, 10, 100 µg/ml) or without fennel extract. In the second series of experiments, cells were cultured with (1, 10, 100 ng/ml) or without ghrelin, alone or in combination with fennel extract (10 µg/ml). Expression of the proliferation marker, PCNA, and the apoptosis marker, bax, were analyzed via quantitative immunocytochemical methods. Fennel stimulated the accumulation of the proliferation marker, and suppressed the expression of the apoptosis marker. Ghrelin alone promoted proliferation and apoptosis of ovarian cells. The presence of fennel inhibited these ghrelin effects. These observations provide the first demonstration of (1) effects of fennel on farm animal reproduction, (2) direct effects of fennel on ovarian cells, (3) the ability of fennel to promote ovarian cell proliferation, to inhibit ovarian cell apoptosis, and to enhance the ovarian cell proliferation:apoptosis ratio. Furthermore, our results (4) confirm the involvement of ghrelin in the control of ovarian cell apoptosis and proliferation, and (5) demonstrate the ability of fennel to affect not only ovarian cell proliferation and apoptosis, but also to suppress the responses of ovarian cells to the upstream hormonal regulator ghrelin. Our results indicate the potential applicability of fennel as a bio-stimulator of farm animal reproduction.